Flight From Risk Extends Beyond Apple

A sharp sell-off in an array of closed-end funds may be canaries in the increasingly risky coal mine of the market.

Only buy stocks that go up. If they don't go up, don't buy them. That was the investment advice offered by the late humorist Will Rogers, and it seems to be followed by investors as much as ever.

That has led them to flock to Apple (ticker: AAPL) at its peak of $705.07 a share in September and to flee the stock en masse as it dropped to a six-month low Thursday of $525.62. As of this writing, it fell another $11.14, or 2.1%, to a...